See, my dad was shitty to my mom. Cheating on her is awful. Cheating on her repeatedly is even worse. Even as a kid I could see the psychological damage it did to her. And having experienced it in my young 20s, I sympathize with her even more.
The lady my dad ended up with was a friend of the family and knew damn well he was married.
My mom never ever asked me to dislike my step mom, but I always decided it on my own. What they did is fucked up, and even as a kid I understood that.
I'm old enough now that I'm civil with both of them. I'm cool with my dad and I have been for many years. I don't hate him for what he did but I sure as fuck will not ever approve of it. We talk multiple times per week, but bet I see my mom every day.
Idk. Everyone is different I guess.